Amendments to a will may be made by codicil. But that requires the same formalities as the original will did and a completely new will would. So there is no point in it; it's as much trouble as rewriting the existing will.
A codicil has its uses. But they are confined, in practice and common sense, to wills which are enormously complicated. Then, rather than going to all the trouble of redoing the whole thing, when all that is required is a minor alteration, it may be worthwhile. But the trouble with all codicils is that the codicil itself may be lost, or someone may not realise that it exists, since there is no clue in the original will that the codicil exists.
well one of my ancestors did it in 1820 - disinherited one of his children by codicil. I think it was the eldest - God they must have got p+ssed off with him...
I would have thought for clarity's sake - do another one.
When we made our wills, the solicitor who did it said that codicils are falling into disuse in professionally written wills simply because more and more, the solicitor keeps an electronic copy, so its easy, and less subject to later error, to make the changes within the body of the will and produce a new will. When wills were hand written or typed, adding a codicil was much less work, therefore cost less, than rewriting the whole will.